A professor at the University of Sydney  was giving a lecture on 'Involuntary Muscular Contractions' to his first year medical students. Realising this was not the most riveting subject, the professor decided to lighten the mood slightly. He pointed to a young woman in the front row and said, 'Do you know what your rsehole is doing while you're having an orgasm?'   

She replied, 'Probably fishing with his mates.'

good

I resent that i was in the pub not fishing lol